According to the NHS Britain is the most obese nation in western Europe. A quarter of adults are obese. Levels of obesity have risen threefold on thirty years, and if trends continue half the population will be obese by 2050. Diabetes, heart disease and cancer are just a few of the diseases that can follow from being obese. The consequences, for individuals and for the NHS, are obvious.

What’s to blame? Poor diet, certainly, but also physical inactivity. And the solution? For many, and especially for politicians, there is a simple answer to low levels of physical inactivity. Sport. More sport. More sport for all.

This is one of the most powerful and least challenged assumptions in public policy. Almost everyone seems to believe that sport is the most obvious, even the only way of keeping our bodies active and controlling our weight. Governments will do nothing or almost nothing to help us choose to eat better, but hardly a week goes by without some minister pledging more money to support sport or exhorting us to take up a competitive sport.

True, politicians push sport for another reason. It’s claimed, with some justification, that money pumped into elite sport will allow us to beat other countries, at least in a handful of sports like running and boating, and especially if the next Olympic Games is coming somewhere close. Now that we lack an empire, gunboats and aircraft carriers to defeat other countries by military means, sporting ‘excellence’ is generally taken to be a symbolic national objective of some importance. But usually it’s assumed that official support for sport can kill two birds with one stone: that it will simultaneously lift us higher in world sport rankings and transform the fitness and health of ordinary people. Sport Wales, the government body responsible for funding and encouraging sport, has two formal aspirations: ‘a nation of champions’ and ‘every child hooked on sport for life’, as if these have a necessarily complementary relationship, and as if both are equally achievable.

The problem is that there’s no evidence that state support for sport has any effect on aggregate levels of physical fitness. In fact, the reverse is true. The government poured an eventual £8.8bn into sport in advance of the London Olympics in 2012 with the explicit intention, in part, of increasing participation in sport and hence make people fitter. The thinking of luminaries like Lord Coe was that the glow of British success in the Olympic stadia would somehow rub off on Joe and Jolanda Bloggs and their children, and fire them to take up, if not rowing, fencing and kick-boxing, at least football or swimming. But this is not what’s happened. In fact there’s been a decrease in participation in sport since the Games. In England, according to the Local Government Association, there’s been a drop of nearly half a million since 2012 in the number of people taking part on grassroots sport. Even Sport England, which has self-interest in trumpeting success, admits that participation rates for people in low socio-economic groups and disabled people are static or falling and remain low. The Sports Minister, Tracey Crouch, now says she’s ‘ripping up’ the previous sports strategy, where most money went to the governing bodies of individual sports, and starting again. The overwhelming stress is still on sport, but there’s an interesting feature of the new approach, a ‘shift in emphasis away from only funding formal sport to more general fitness’, and a recognition that you need to start with young children.

Here in Wales I found it difficult to track down up-to-date statistics for sports participation, but it seems unlikely the picture is very different. According to Sport Wales, a survey of adults in 2012, the year of the Olympics, revealed that only 38% of people in Wales agreed with the statement, ‘it’s important to me to take part in sport or exercise regularly’. Wales as a whole has a higher percentage of obese children (26%) than the worst region of England (24%); more than a quarter of Welsh children are obese before they start school.

All the evidence suggests that pushing sports participation as the principal means of producing an active, fit and healthy population is an almost complete failure.

Research on why this should be so seems to be scarce (why would sports organisations or university sports science departments sponsor research to show that sport is ineffective?). But it’s not hard to think of reasons why people fail to heed the calls and inducements to take up sport. For example, it takes time, effort and money – to find a club or team to join, to buy equipment and clothing, to travel to sports venues, to devote a day or half a day to activity. Many local sports facilities are now under pressure from the government’s austerity programme. Much more important, I suspect, is the fact that a large proportion of people find competitive sport unappealing, especially if they’re expected to take part in it rather than watch it. When I started in secondary school I couldn’t wait for the time when I was allowed to give up rugby – shivering out on the wing and hoping that I wouldn’t get flattened by the brutes opposite if the ball did come my way – and take up cross-country running. Cross-country held an element of competition only for the sporting nerds who came home quickest, and it could even be enjoyed by the rest of us as we padded slowly through the soaking woods and rhubarb fields of west Yorkshire. Competition may be an inescapable part of our turbo-capitalist age, that that doesn’t mean that it’s a universal part of human nature, and there are still many people for whom struggling to beat their fellow humans holds little attraction. Sport is not for all.

If bullying the population to take up sport is ineffective, and if the aspiration ‘every child hooked on sport for life’ is bound to remain a pious aspiration, never a reality, what should governments do to get us all to be more active? It seems to me that Tracey Crouch is inching towards a better solution, in her emphasis on young children, and in particular on activities that are not sport. Rather than trying to get people to do what they find unappealing, governments would do better to encourage physical activities that are – or should be – a natural part of everyday life. Like ordinary locomotion. Personal motion used to be on two feet but is now, all too often and unnecessarily, on four wheels.

Take going to school as an example. Our local primary school, like most, is under siege twice a day by dozens of cars, some of them monstrous juggernauts, in which parents cart their little ones like Cleopatras in gilded barges, when it would be much better for them, the children, to walk to and from school. The reason they don’t is partly because it never occurs to them or their parents, but mainly because walking or cycling is thought to be too dangerous. So, authorities that were really determined to change things would use their planning powers and their budgets to make walking safer in the school’s neighbourhood. They would pedestrianise roads and create new walking routes, impose 20mph restrictions for vehicles, increase the number of lollipop persons at points of possible danger, and install cycle ways and parking for bikes. Schools would offer not just sport and playground time but other non-competitive activities that consume children’s energy; they might even reinstate ‘nature walks’, now extinct but a regular part of the school timetable fifty years ago. And they would assume that walking and cycling to school was the norm. Unnecessary motorised transport would be regarded as quaint, old-fashioned and socially disreputable.

Now replicate this approach across all age groups and all common everyday activities to remove what are called (horribly) ‘obesogenic environments’, and there’s a much better chance of reversing the trend to a sedentary, passive and unhealthy lifestyle. It won’t be easy. There are vested interests waiting to hobble such a programme, just as Big Food corporations can stifle any effort by governments to discourage unhealthy eating. And it relies on collaboration between different departments of government, always difficult. But if obesity is the biggest single health threat facing the country, it’s worth a try.

I missed Carwyn Jones when he came to Swansea on his ‘Carwyn Connects’ listening tour of Wales as preparation for the Assembly elections next year. But if I’d been there I’d have asked him whether, as part of the Assembly Government’s faltering campaign to discourage physical inactivity (‘physical activity levels have remained relatively constant’), he’d consider abolishing Sports Wales, letting elite sports fend for themselves, and direct money, through a well-funded all-government programme, towards non-competitive ways of promoting activity and fitness, especially walking, running and cycling. And place a duty on all public bodies to make it easier and more natural for everyone, young and old, to make more use of their bodies, rather than cars, lifts and other devices, in their everyday lives.

I can imagine Carwyn’s reaction. He’d smile kindly and prepare a gently dismissive response to the latest crackpot suggestion by a crank from the great Welsh public. But maybe, just maybe, the seed would be sown, and on his way home he‘d start to wonder whether there was not something in the idea. Even if a Tory minister in England got there first.